PO191 Engine Light on E450 Class C RV

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Mar 9, 2025 | 12:26 AM

#16

CathedralCub

FTE Community Team

Joined: Jan 2019

Posts: 10,739

Likes: 1,498

Quote:

Originally Posted by BSO2012

Thank you for responding. I will follow your suggestions. Will let you know what happens. Thank you

Since this thread has been brought back to life, I'm curious @BSO2012: what happened with yours?

Mar 9, 2025 | 08:28 AM

#17

Big Mama

6th Gear

Joined: Mar 2025

Posts: 6

Likes: 5

I’m getting the filter this week and will delete the code and look for any others and report back. I need to “unwinterize” it and fire up the generator too.

Mar 23, 2025 | 07:46 AM

#18

Big Mama

6th Gear

Joined: Mar 2025

Posts: 6

Likes: 5

Yesterday I removed the dog house to look for loose or frayed wires a the FPS and watched live data using my OBD scanner. Moving the wires around did not change the psi. For the most part the psi stayed between 42 and 45 psi. Which sounds to me like the pump and filter are ok based on my research showing psi should be between 28-45. Is that right? I ordered a new FPS that’ll be here tomorrow. It’s an inexpensive part so I don’t mind swapping it out. What do y’all think?

Thanks in advance,
Steven

Mar 23, 2025 | 09:12 AM

#19

QuiGonJohn

6th Gear

Joined: Jul 2023

Posts: 6

Likes: 4

Quote:

Originally Posted by Big Mama

I ordered a new FPS that’ll be here tomorrow. It’s an inexpensive part so I don’t mind swapping it out. What do y’all think?

I don't know what nominal pressures should be. But it won't hurt to change the FPS.

Jul 9, 2025 | 07:21 PM

#20

nigel1

1st Gear

Joined: Jul 2025

Posts: 1

Likes: 1

Same 2005 E450 RV check engine light PO191

Quote:

Originally Posted by QuiGonJohn

I don't know what nominal pressures should be. But it won't hurt to change the FPS.

I changed the fuel rail pressure sensor, changed the fuel filter, put in a new fuel pump and fuel control module. Went for a drive and the RV was running great. Filled with gas and check engine is back on. Same PO191 code. What is wrong with these Ford E450s?!

Jul 9, 2025 | 08:21 PM

#21

QuiGonJohn

6th Gear

Joined: Jul 2023

Posts: 6

Likes: 4

Wow, I got a new Fuel Control Module, but never replaced it. And would only do the fuel pump as a last resort. So the last time I had gotten the code was in mid-May 2023, the morning we left out of Dickinson, ND. Heading W towards Belfield, RV went into passing gear on cruise and the light came on. Stopped in Belfield, my brother-in-law, who has a mechanic shop checked it all out, cleared the code. After we got home, I had a shop I trust check everything out and if they would have said the Fuel Pump needed to be replaced, I'd have done it. But they said it was fine. We drove it quite a bit over the next 2 years. But in early June 2025, driving in Oregon, between Klamath Falls and Bend, RV went into passing gear again, and I got the light. Had the code checked at Advance Auto in Bend, P-191 Code. I cleared the code myself. We drove the rest of our trip, ID, MT, ND, MN, IA, IL, KY, TN and back to FL, never got it again. It's just weird.